When designing a robot, is it better to use wheels or to give it legs?
This is more than just a design challenge. There’s a lot of little things to consider when you design a robot, primarily if you have limited resources on hand. It is essential that you have an idea what to do with those resources and how to make the most of what’s available.
With all of that in mind, which would be better?
On the one hand, legs are much harder to program correctly. Walking seems simple, but is incredibly complex and requires a great deal of coordination to pull off successfully. Programming that when you don’t have a huge budget can be a hassle.
However, legs also allow for more significant interaction. Standard environments like stairs and rough terrain are easier to navigate with legs and feet, rather than wheels. If you can program the machinery to adjust on the fly, you’ll have something with better mobility.
On the other hand, wheels are easier to manage. There’s plenty of technology out there for managing wheels on machines.
Cars, especially ones designed for the outdoors, have a long history of having systems that allow wheels and tire systems to adjust to terrain. Wheel alignments, tire pressure, and the like can all be monitored and updated, allowing for greater control.
Simply put, we are very good at maintaining things that have wheels. The technology is much more available and easier to manage.
Wheeled systems are fast. Faster than any other system we know of unless it’s in the air. However, they’re not agile. Agility and speed are not the same things. Wheels provide great speed in linear motion, but legs are better for sharp turns and traversing routes other than a straight line.
Legs and arms provide a means of movement that wheels don’t: the vertical.
With arms and legs, you can perform a vertical climb. Wheels don’t allow this, even with the best traction available. You need a stable grip. With real estate starting to go up instead of sideways, the ability to keep pace with it is a smart move.
Amusingly enough, legs are more stable than wheels. At least, once you get the elements of balancing the robots down.
For many years, wheels were the optimal choice. However, we have gotten better at building robots with legs that can coordinate and move without too much trouble.